Nomogram to predict the risk of adverse outcomes in patients with residual stones following percutaneous nephrolithotomy

ABSTRACT Purpose: To investigate the risk factors associated with adverse outcomes in patients with residual stones after percutaneous nephrolithotomy (PCNL) and to establish a nomogram to predict the probability of adverse outcomes based on these risk factors. Methods: We conducted a retrospective review of 233 patients who underwent PCNL for upper urinary tract calculi and had postoperative residual stones. The patients were divided into two groups according to whether adverse outcomes occurred, and the risk factors for adverse outcomes were explored by univariate and multivariate analyses. Finally, we created a nomogram for predicting the risk of adverse outcomes in patients with residual stones after PCNL. Results: In this study, adverse outcomes occurred in 125 (53.6%) patients. Multivariate logistic regression analysis indicated that the independent risk factors for adverse outcomes were the diameter of the postoperative residual stones (P < 0.001), a positive urine culture (P = 0.022), and previous stone surgery (P = 0.004). The above independent risk factors were used as variables to construct the nomogram. The nomogram model was internally validated. The calculated concordance index was 0.772. The Hosmer- Lemeshow goodness-of-fit test was performed (P > 0.05). The area under the ROC curve of this model was 0.772. Conclusions: Larger diameter of residual stones, positive urine culture, and previous stone surgery were significant predictors associated with adverse outcomes in patients with residual stones after PCNL. Our nomogram could help to assess the risk of adverse outcomes quickly and effectively in patients with residual stones after PCNL

One week pre-operative oral antibiotics for percutaneous nephrolithotomy reduce risk of infection: a systematic review and meta-analysis

ABSTRACT Purpose The aim of this meta-analysis is to assess the efficacy of extended dose of preoperative antibiotics to reduce infectious risk in patients undergoing percutaneous nephrolithotomy (PCNL). Materials and Methods A literature search for prospective case-control studies or randomized controlled trials was done. PICO framework was used. Population: adult patients that underwent to PCNL; Intervention: extended dose preoperative antibiotic prophylaxis before PCNL; Control: short dose preoperative antibiotic prophylaxis before PCNL; and Outcome: systemic inflammatory response syndrome (SIRS) or sepsis, fever after PCNL and positive intraoperative urine and stone culture. This meta-analysis was registered in PROSPERO database under the number: CRD42022359589. Results Three RCT and two prospective studies (475 patients) were included. SIRS/sepsis outcome was retrieved from all studies included. Seven days preoperative oral antibiotics for PCNL was a protective factor for developing SIRS/sepsis (OR 0.366, 95% CI 0.234 - 0.527, p < 0.001). There was no statistical association between seven-day use of antibiotics and fever (OR 0.592, 95% CI 0.147 - 2.388, p = 0.462). Patients who received seven days preoperative antibiotics had lower positive intraoperative urine culture (OR 0.284, 95% CI 0.120 - 0.674, p = 0.004) and stone culture (OR 0.351, 95% CI 0.185 - 0.663, p = 0.001) than the control group. Conclusion one week of prophylactic oral antibiotics based on local bacterial sensitivity pattern plus a dose of intravenous antibiotics at the time of surgery in patients undergoing PCNL reduces the risk of infection.

Complicaciones frecuentes en pacientes con nefrolitotomía percutánea / Common complications in patients with percutaneous nephrolithotomy

RESUMEN La nefrolitotomía percutánea es un procedimiento estandarizado para el tratamiento de la litiasis renal. El objetivo de esta comunicación fue describir las complicaciones que más incidieron en los pacientes que fueron atendidos en el Hospital Universitario Clínico-Quirúrgico «Arnaldo Milián Castro¼, en el servicio de Urología, de enero de 2015 a diciembre de 2019, a los cuales se les realizó nefrolitotomía percutánea, así como el tratamiento que recibieron y su evolución. Este estudio mostró bajo índice de complicaciones, lo que guarda relación con el poco tiempo utilizado para realizar esta técnica. Esto resultó beneficioso ya que contribuyó a la corta estadía hospitalaria y disminuyó el consumo de materiales e insumos médicos. También representa un gran logro para los médicos y sobre todo para el paciente, el cual puede recuperarse en un menor período de tiempo y vincularse rápidamente a su vida diaria.

ABSTRACT Percutaneous nephrolithotomy is a standardized procedure for the treatment of kidney stones. The objective of this communication was to describe complications, treatment and evolution of patients who underwent a percutaneous nephrolithotomy in the Urology service at "Arnaldo Milián Castro" Clinical and Surgical University Hospital from January 2015 to December 2019. This study showed a low rate of complications, which is related to the short time used to perform this technique. This was beneficial since it contributed to the short hospital stay and decreased the consumption of medical materials and supplies. It also represents a great achievement for doctors and above all for the patients, who can recover in a shorter period of time and be quickly returned to their daily life.

A novel nomogram and a simple scoring system for urinary leakage after percutaneous nephrolithotomy

ABSTRACT Introduction: The present study aimed to investigate the factors of prolonged urinary leakage (PUL) after percutaneous nephrolithotomy (PCNL) and develop a new and simple scoring system to predict it. Patients and Methods: We retrospectively reviewed patients with renal stones who underwent PCNL at the University of Health Sciences Izmir Bozyaka Training and Research Hospital between April 2011 and January 2020. The patients were divided into two groups according to the presence of PUL, and their preoperative and perioperative data were compared. A multivariate regression analysis was applied to examine the relationship between perioperative descriptors and PUL, and a nomogram was developed using significant predictors. Then, the individual components of the nomogram were assigned points to form a scoring system. Results: There were 92 and 840 patients in the groups with and without PUL, respectively. The results of the univariate logistic regression analysis showed that hydronephrosis grade, parenchymal thickness, duration of nephroscopy, and duration of nephrostomy catheter were significantly associated with PUL. Subsequently, a multivariate regression analysis was carried out with these four factors as possible independent risk factors of PUL after PCNL. Based on the results of this analysis, a nomogram prediction model was developed with an area under the curve value of 0.811, which was consequently used to develop a new simple score system consisting of three characteristics: parenchymal thickness (1-5 points), duration of nephroscopy (1-3 points), and hydronephrosis grade (1-3 points). Conclusion: A novel scoring system is a useful tool for predicting PUL in patients who have undergone percutaneous nephrolithotomy.

Comparison of mini percutaneous nephrolithotomy and standard percutaneous nephrolithotomy for renal stones >2cm: a systematic review and meta-analysis

ABSTRACT Background The purpose is to compare the efficacy and safety of mini percutaneous nephrolithotomy (mini-PCNL) versus standard percutaneous nephrolithotomy (standard-PCNL) in patients with renal stones >2cm. Materials and Methods A systematic literature search was conducted in PubMed, Web of Science, Scopus, and the Cochrane Library databases to identify relevant studies before March 8, 2021. Stone-free rate (SFR), operation time, fever rate, hemoglobin drop, blood transfusion rate, and hospitalization time were used as outcomes to compare mini-PCNL and standard-PCNL. The meta-analysis was performed using the Review Manager version 5.4. Results Seven randomized controlled trials were included in our meta-analysis, involving 1407 mini-PCNL cases and 1436 standard-PCNL cases. Our results reveal that, for renal stones >2cm, mini-PCNL has a similar SFR (risk ratio (RR)=1.01, 95% confidence interval (CI): 0.98 to 1.04, p=0.57) and fever rate (RR=1.22, 95% CI: 0.97-1.51, p=0.08). Standard-PCNL was associated with a significantly shorter operating time (weighted mean difference (WMD)=8.23, 95% CI: 3.44 to 13.01, p <0.01) and a longer hospitalization time (WMD=-20.05, 95% CI: -29.28 to -10.81, p <0.01) than mini-PCNL. Subgroup analysis showed hemoglobin drop and blood transfusion for 30F standard-PCNL were more common than mini-PCNL (WMD=-0.95, 95% CI: -1.40 to -0.50, p <0.01; RR=0.20, 95% CI: 0.07 to 0.58, p <0.01). Conclusion In the treatment of >2cm renal stones, mini-PCNL should be considered an effective and reliable alternative to standard-PCNL (30F). It achieves a comparable SFR to standard-PCNL, but with less blood loss, lower transfusion rate, and shorter hospitalization. However, the mini-PCNL does not show a significant advantage over the 24F standard-PCNL. On the contrary, this procedure takes a longer operation time. Trial registration This meta-analysis was reported consistent with the PRISMA statement and was registered on PROSPERO, with registration number 2021CRD42021234893.

Complicaciones de la nefrolitotomía percutánea como tratamiento de la litiasis renal coraliforme

RESUMEN Introducción: La nefrolitotomía percutánea es la primera opción terapéutica para la litiasis renal coraliforme. Objetivo: Caracterizar a los pacientes con complicaciones de la nefrolitotomía percutánea para el tratamiento de la litiasis renal coraliforme. Método: Se estudió una serie de 191 pacientes, operados mediante nefrolitotomía percutánea. Variables estudiadas: tipo de litiasis coraliforme, posición para la técnica, condición de libre de litiasis después de la operación, presencia de complicaciones, momento, tipo y grado según clasificación de Clavien-Dindo. Se hallaron frecuencias absolutas, relativas y se utilizó el test de ji cuadrado para determinar asociación entre variables. Resultados: El 86,9 % tenía menos de 60 años, 67,0 % eran masculinos, 61,7 % presentaba comorbilidades. La litiasis coraliforme era parcial o total (30,3 % y 46,5 %, respectivamente). En 60,2 % afectaba el riñón izquierdo; 58,1 % se operaron en supino y 70,2 % quedaron libre de litiasis con la nefrolitotomía percutánea monoterapéutica. Ocurrieron complicaciones en 19,9 %; 16,2 % fueron postoperatorias, 14,1 % infecciosas, 7,8 % Clavien-Dindo I y 5,2 % IIIb. El tipo de litiasis y la posición de la nefrolitotomía percutánea no se asociaron con las complicaciones (p> 0,05). El grado de la complicación no se relacionó con el tipo de litiasis (p> 0,05). Conclusiones: Las complicaciones postoperatorias más frecuentes son las relacionadas con la infección y el sangrado; predominan ligeramente en los pacientes con litiasis coraliformes parcial, total y en los operados en supino; el grado Clavien-Dindo de las complicaciones, es mayor en las litiasis coraliformes más complejas.

ABSTRACT Introduction: Percutaneous nephrolithotomy is the first therapeutic option for staghorn kidney stones. Objective: To characterize patients with complications of percutaneous nephrolithotomy for the treatment of staghorn renal lithiasis. Method: A series of 191 patients, operated by percutaneous nephrolithotomy, was studied. Variables studied: type of staghorn lithiasis, position for the technique, stone-free condition after the operation, presence of complications, time, type and grade according to the Clavien-Dindo classification. Absolute and relative frequencies were found and the chi-square test was used to determine the association between variables. Results: 86.9 % were less than 60 years old, 67,0 % were male, 61,7 % had comorbidities. The staghorn lithiasis was partial or total (30,3 % and 46,5 %, respectively). In 60,2 % it affected the left kidney; 58.1 % underwent supine surgery and 70,2 % were stone free with monotherapeutic percutaneous nephrolithotomy. Complications occurred in 19,9 %; 16,2 % were postoperative, 14,1 % infectious, 7,8 % Clavien-Dindo I, and 5,2 % IIIb. The type of lithiasis and the position of the percutaneous nephrolithotomy were not associated with complications (p> 0,05). The degree of complication was not related to the type of lithiasis (p> 0,05). Conclusions: The most frequent postoperative complications are those related to infection and bleeding; they slightly predominate in patients with partial and total staghorn stones and in those operated on in the supine position; the Clavien-Dindo grade of complications is higher in the more complex staghorn stones.

Does previous standard percutaneous nephrolithotomy impair retrograde intrarenal surgery outcomes?

ABSTRACT Purpose: The objective of this study is to evaluate the impact of a previous standard percutaneous nephrolithotomy (PCNL) on the outcomes of retrograde intrarenal surgery (RIRS). Materials and Methods: Outcomes of RIRS performed from January 2017 to January 2020 in adult patients with residual stone fragments ≤20mm after a standard PCNL (Post-PCNL) and symptomatic adult patients with kidney stones ≤20mm (Control) were prospectively studied. Stone-free rate (SFR) was evaluated on a postoperative day 90 non-contrast computed tomography. Surgical complications based on Clavien-Dindo classification during the 90 days of follow-up were recorded. Results: Outcomes of 55 patients and 57 renal units of the post-PCNL group were compared to 92 patients and 115 renal units of the control group. SFR was lower in post-PCNL group than in control (28/57, 49.1% vs. 86/115, 74.8%, p <0.001). Overall complications were more frequent in post-PCNL group (p=0.004). Infundibula strictures were identified and incised with laser in 15/57 (26.3%) renal units of the post-PCNL group. Thirteen renal units had infundibulum stricture at the site of previous percutaneous tract (13/15; 86.7%, p=0.004) and one renal unit had three infundibula strictures. Postoperative complications were not affected by the treatment of infundibula strictures (p=0.198). Conclusions: Previous standard PCNL significantly impairs the outcomes of RIRS. Infundibula strictures can be found in 26.3% of the patients with residual stone fragments after standard PCNL for large burden kidney stones. The main site of infundibulum stricture after standard PCNL is the infundibulum of the entry calyx.

Patients with encrusted ureteral stents can be treated by a single session combined endourological approach

ABSTRACT Purpose: To describe our experience in the management of retained encrusted ureteral stents using a single session combined endourological approach. Materials and Methods: Patients with retained encrusted ureteral stents who had been submitted to a single session combined endourological approach from June 2010 to June 2018 were prospectively evaluated. Patients were divided according to the Forgotten-Encrusted-Calcified (FECal) classification. The stone burden, surgical intervention, number of interventions until stone free status, operation time, hospital stay, complications, stone analysis, and stone-free rate were compared between groups. ANOVA was used to compare numerical variables, and the Mann-Whitney or Chi-square test to compare categorical variables between groups. Results: We evaluated 50 patients with a mean follow-up of 2.9±1.4 years (mean±SD). The groups were comparable in terms of age, sex, laterality, BMI, comorbidities, ASA, reason for stent passage, and indwelling time. The stone burden was higher for grades IV and V (p=0.027). Percutaneous nephrolithotomy was the most common procedure (p=0.004) for grades IV and V. The number of procedures until the patients were stone-free was 1.92±1.40, and the hospital stay (4.2±2.5 days), complications (22%), and stone analysis (66% calcium oxalate) were similar between groups. The stone-free rate was lower in grades III to V (60%, 54.5%, and 50%). Conclusions: The endoscopic combined approach in the supine position is a safe and feasible technique that allows removal of retained and encrusted stents in a single procedure. The FECal classification seems to be useful for surgical planning.

Hemorrhagic complications after percutaneous nephrolithotomy: angiographic diagnosis and management by transcatheter arterial embolization / Complicações hemorrágicas após nefrolitotripsia percutânea: diagnóstico angiográfico e tratamento por embolização arterial transcateter

Abstract Objective: To identify the main hemorrhagic complications after percutaneous nephrolithotomy, as well as the results obtained with transcatheter arterial embolization (TAE) at an interventional radiology center. Materials and Methods: This was a retrospective analysis of patients undergoing TAE for the treatment of hemorrhagic complications after percutaneous nephrolithotomy. All patients underwent computed tomography angiography (CTA). Results: We evaluated a total of nine patients. At emergency department readmission, the most common symptom was macroscopic hematuria, which was seen in five patients. Three patients had an isolated pseudoaneurysm, two had a pseudoaneurysm together with active bleeding (perirenal hematoma), and one had a pseudoaneurysm together with arteriocalyceal fistula. Arteriovenous fistula was diagnosed in three patients and was not seen in combination with other vascular lesions. We did not identify arteriocalyceal fistula in isolation. Five patients underwent TAE with 6 × 15 mm and 6 × 20 mm microcoils. Four patients underwent TAE with n-butyl-2-cyanoacrylate and ethiodized oil. Follow-up CTAs revealed no complications. Conclusion: Because of its high diagnostic accuracy, CTA provides the interventional radiologist with valuable data for individualized therapeutic planning. The TAE procedure is safe and effective. It can therefore be used as a first-line treatment for hemorrhagic complications resulting from percutaneous renal procedures.

Resumo Objetivo: Demonstrar as principais complicações hemorrágicas após nefrolitotripsia percutânea, bem como os resultados após o tratamento por embolização arterial transcateter (EAT) em um centro de radiologia intervencionista. Materiais e Métodos: Coleta e análise de dados retrospectivos de pacientes submetidos a EAT por complicações hemorrágicas após nefrolitotripsia percutânea. Resultados: O sintoma mais comum foi hematúria macroscópica, presente em cinco pacientes no momento da readmissão ao pronto-socorro, e nestes pacientes identificamos três pseudoaneurismas isolados, dois casos de combinação de pseudoaneurisma e sangramento ativo (hematoma perirrenal) e um caso de associação de pseudoaneurisma e fístula arteriocalicinal. Fístula arteriovenosa foi diagnosticada em três pacientes, não sendo observada em associação com outras lesões vasculares. Não identificamos fístula arteriocalicinal isolada, somente associada a pseudoaneurisma. Cinco pacientes foram submetidos a embolização por micromolas 6 × 15 mm e 6 × 20 mm. Quatro pacientes foram submetidos a embolização por Histoacryl e Lipiodol. Não observamos complicações pela angiotomografia computadorizada de controle. Conclusão: A angiotomografia computadorizada apresenta alta acurácia diagnóstica e guarnece o radiologista intervencionista de dados para um planejamento terapêutico individualizado. EAT é um procedimento seguro e eficaz e pode ser utilizado como primeira linha para o tratamento de complicações hemorrágicas resultantes de procedimentos percutâneos renais.

Efficacy and safety of various surgical treatments for proximal ureteral stone ≥10mm: A systematic review and network meta-analysis

ABSTRACT Purpose Various surgical options are available for large proximal ureteral stones, such as extracorporeal shock wave lithotripsy (ESWL), ureteroscopic lithotripsy (URSL), percutaneous nephrolithotomy (PCNL) and laparoscopic ureterolithotomy (LU). However, the best option remains controversial. Therefore, we conducted a network meta-analysis comparing various surgical treatments for proximal ureteral stones ≥10mm to address current research deficiencies. Materials and methods We searched PubMed, Ovid, Scopus (up to June 2019), as well as citation lists to identify eligible comparative studies. All clinical studies including patients comparing surgical treatments for proximal ureteral stones ≥10mm were included. A standard network meta-analysis was performed with Stata SE 14 (Stata Corp, College Station, TX, USA) software to generate comparative statistics. The quality was assessed with level of evidence according to the Oxford Centre for Evidence-based Medicine and risk of bias with the Cochrane Collaboration's Review Manager (RevMan) 5.3 software. Results A total of 25 studies including 2.888 patients were included in this network meta-analysis. Network meta-analyses indicated that LU and PCNL had better stone-free rates and auxiliary procedures. PCNL could result in major complications and severe bleeding. In initial stone-free rate, final stone-free rate, and auxiliary procedures results, SUCRA ranking was: LU> PCNL> URSL> ESWL. In Clavien Dindo score ≥3 complications, SUCRA ranking was: LU> ESWL> URSL> PCNL. In fever, SUCRA ranking was: ESWL> LU> URSL> PCNL. In transfusion, SUCRA ranking was: LU> URSL> ESWL> PCNL. In Cluster analysis, LU had the highest advantages and acceptable side effects. Considering the traumatic nature of PCNL, it should not be an option over URSL. ESWL had the lowest advantages. Conclusions LU have the potential to be considered as the first treatment choice of proximal ureteral stone ≥10mm.

Factors affecting fluoroscopy time during percutaneous nephrolithotomy: Impact of stone volume distribution in renal collecting system

ABSTRACT Purpose: To identify the factors increased fluoroscopy time during percutaneous nephrolithotomy and investigate the relationship between the 3D segmentation volume ratio of stone to renal collecting system and fluoroscopy time. Materials and Methods: Data from 102 patients who underwent percutaneous nephrolithotomy were analyzed retrospectively. Volume segmentation of both the renal collecting system and stones were obtained from 3D segmentation software with the images on CT data. Analyzed stone volume (ASV), renal collecting system volume (RCSV) measured and the ASV-to-RCSV ratio was calculated. Several parameters were evaluated for their predictive ability with regard to fluoroscopy time. Results: The stone-free rate was 55.9% after the percutaneous nephrolithotomy. Complications occurred in 31(30.4%) patients. The mean fluoroscopy time was 199.4±151.1 seconds. The fluoroscopy time was significantly associated with the ASV-to-RCSV ratio (p<0.001, r=0.614). The single tract was used in 77 (75.5%) cases while multiple tracts were used in 25 (24.5%) cases. Fluoroscopy time was significantly associated with multiple access (p<0.001, r=0.689). On univariate linear regression analysis, longer fluoroscopy time was related with increased stone size, increased stone volume, increased number of access, increased calyx number with stone, increased ASV-to-RCSV, increased operative time and decreased stone essence. On multivariate linear regression analysis, the number of access and the ASV-to-RCSV were independent predictors of fluoroscopy time during percutaneous nephrolithotomy. Conclusions: The distribution of the stone burden volume in the pelvicalyceal system is a significant predictor for prolonged fluoroscopy time during percutaneous nephrolithotomy. Measures to decrease FT could be beneficial in patients with a high ASV-to-RCSV ratio for precise preoperative planning.

Comparison of supine and prone miniaturized percutaneous nephrolithotomy in the treatment of lower pole, middle pole and renal pelvic stones: A matched pair analysis

ABSTRACT Purpose We aimed to compare the outcomes of supine and prone miniaturized percutaneous nephrolithotomy (m-PNL) in the treatment of lower pole, middle pole and renal pelvic stones. Materials and Methods 54 patients who performed supine m-PNL between January 2017 and March 2018 and 498 patients who performed prone m-PNL between April 2015 and January 2018 were included in the study. Of the 498 patients, 108 matching 1: 2 in terms of age, gender, body mass index, American Association of Anesthesiology score, stone size, stone localization and hydronephrosis according to the supine m-PNL group were selected as prone m-PNL group. The patients with solitary kidney, upper pole stone, urinary system anomaly or skeletal malformation and pediatric patients (<18 years old) were excluded from the study. The success was defined as 'complete stone clearance' and was determined according to the 1st month computed tomography. Results The operation time and fluoroscopy time in supine m-PNL was significantly shorter than prone m-PNL group (58.1±45.9 vs. 80.1±40.0 min and 3.0±1.7 min vs. 4.9±4.5 min, p=0.025 and p=0.01, respectively). When post-operative complications were compared according to the modified Clavien-Dindo classification, overall and subgroup complication rates were comparable between groups. There was no significant difference between the groups in terms of the success rates (supine m-PNL; 72.2%, prone m-PNL; 71.3%, p=0.902). Conclusions Supine m-PNL procedure is more advantageous in terms of operation time and fluoroscopy time in the treatment of lower pole, middle pole and renal pelvic stones.

A prospective study assessing feasibility of performing percutaneous nephrolithotomy in chronic kidney disease patients - What factors affect the outcome?

ABSTRACT Objectives To primarily evaluate the functional outcomes of PCNL for bilateral renal calculi/calculi in solitary functioning kidney with Chronic Kidney Disease(CKD). To identify factors affecting the renal replacement therapy following PCNL. Materials and Methods Patients with bilateral renal calculi/calculi in solitary kidney and CKD (eGFR<60/s.creatinine>2) and Good Performance Status [Eastern Cooperative Oncology Group (ECOG): 0-2] were included in the study. Results A total of 60 patients with CKD who had bilateral renal calculi/calculi in solitary functioning kidney underwent PCNL. At 6 months, eGFR improved or stabilized in 45 (75%) patients, while in 15 (25%) patients eGFR deteriorated. A total of 5 (14.28%) and 2 (25%) patients of CKD stage 4 and 5 respectively had improvement in eGFR as well as CKD stage. Fourteen (82.35%), 21 (60%), 3 (37.5%) patients of CKD stage 3, 4, 5 had improvement in eGFR but not significant enough to cause stage migration. Again 3 (17.65%) , 9 ( 40%) and 3 (37.5%) patients of CKD stage 3, 4, 5 had reduction in eGFR but not significant enough to cause stage migration. None of the patients had worsening of CKD stage. Preoperative CKD stage and eGFR were compared with measurements made at the final follow up visit (6 months). Conclusion Our results indicate that most patients of renal calculi with CKD show improvement or stabilization of renal function with aggressive stone removal. Improvement is more in patients who have mild to moderate CKD. Aggressive management of comorbidities, peri-operative UTI and complications may delay or avoid progression of CKD status in such patients.

Retrograde vs. antegrade flexible nephroscopy for detection of residual fragments following PNL: a prospective study with computerized tomography control

ABSTRACT Introduction: The main aim of stone surgery is to establish stone free status. Performing flexible nephroscopy is an effective tool in this manner. The aim of this study was to evaluate the role of retrograde flexible nephroscopy for detection of residual fragments following percutaneous nephrolithotomy (PNL) in comparison with antegrade approach. Materials and Methods: Data of 137 patients underwent ECIRS was collected prospectively. In all cases following stone clearance, collecting system was checked for residual fragments. First antegrade than retrograde flexible nephroscopy was performed and success rates to reach all calices and detection of residual fragments were noted. All patients underwent CT and success rate of antegrade and retrograde approaches were compared. PPV and NPV of retrograde approach to detect residual fragments were calculated. Results: Antegrade and retrograde nephroscopy successfully accessed all of the calices in 101 (73.7%) and 130 (94.9%) patients respectively (p<0.0001). Residual fragments were observed in 18 (13.1%) patients following antegrade flexible nephroscopy. Retrograde approach identified residual stones in 17 more cases. These cases were treated with flexible nephroscopy or secondary percutaneous tract. Postoperative CT revealed residual stones in 10 (7.3%) patients. PPV and NPV of retrograde flexible nephroscopy were 83.3% and 96.2%. Conclusions: Flexible nephroscopy effectively detects residual fragments following PNL. Retrograde approach was more successful than antegrade approach to reach all calices. We recommend performing retrograde flexible nephroscopy following PNL especially in complex cases as it has the potential to increase SFR, decrease the need for second look surgery and unnecessary postoperative imaging.

Comparison of three minimally invasive surgical methods in treatment of impacted upper-ureteral calculi / 中华全科医师杂志

One hundred and fifty patients with impacted upper-ureteral calculi were treated with ureteroscopic lithotripsy (URSL group,n =58),percutaneous nephrolithotomy (PCNL group,n =42) or retroperitoneal laparoscopic ureterolithotomy (RPLU group,n =50) from April 2011 to August 2015.The operative time,length of postoperative hospital stay,stone-free rate and the incidence of postoperative complications were observed and compared among three groups.The stone-free rate of URSL group one month after surgery was 77％,which was significantly lower than PCNL (95％) and RPLU groups (100％) (P ＜ 0.05).But the operative time and length of postoperative hospital stay of URSL group [(37.2 ± 5.6)min,(3.9-±0.8)d] were significantly shorter than PCNL group[(75.2 ±6.7) min,(7.9 ±0.9))d] and RPLU group [(65.3 ± 6.1) min,(8.7 ± 0.9) d] (all P ＜ 0.05).The postoperative complication rates of three groups were 8％,10％ and 10％,respectively.

Risk factors analysis for residual stones after MPCNL for the treatment of upper urinary calculi in pediatric patients / 重庆医学

Objective To investigate factors affecting residual stones in pediatric patients with the upper urinary calculi un ‐dergoing minimally invasive percutaneous nephrolithotomy (MPCNL ) and evaluate MPCNL curative effect before the operation . Methods A total of 240 children underwent MPCNL to remove the upper urinary calculi in People′s Hospital of Xinjiang Uygur Autonomous Region during the period of January 2009 to November 2014 were analyzed retrospectively .Pediatric patients were di‐vided into two groups by the stone‐free rate after the first operation :those who were stone‐free after the first operation (n= 202) as the control group and those who were residual stones (n= 38) as residual stones observation group .Then the clinical data were sta‐tistically analyzed and find out risk factors which lead to residual stone .Results The stone‐free rate after primary M PCNL was 84 . 2% (202/240) .Univariate analysis showed that stone size (P= 0 .001) ,stone location(P= 0 .014) and number of stones(P= 0 .005) were significant factors which could affect residual stones between the two groups ,while did not relate with gender ,age ,stone side , urinary irritation symptom ,hematuria ,renal colic ,preoperative infection and the degree of hydronephrosis (P > 0 .05) .Multivariate analysis showed that stone size(OR = 2 .593 ,95% CI :1 .228 - 5 .475) ,stone location(OR = 2 .674 ,95% CI :1 .290 - 5 .540)and num‐ber of stones(OR = 2 .397 ,95% CI :1 .145 - 5 .019)were independent predictors of the surgical outcome .Conclusion Stone size , stone location and number of stones are significant factors affecting residual stones in pediatric patients with the upper urinary cal ‐culi undergoing MPCNL .According to the the clinical features of pediatric patients ,we can chose suitable management of upper uri‐nary tract calculi .

Clinical curative effect comparison of percutaneous nephrolithotomy and flexible ureteroscope lithotripsy for the treatment of renal calculus equal or smaller than 2 cm / 重庆医学

Objective To compare the clinical curative effect of percutaneous nephrolithotomy (PCNL) and flexible uretero‐scope lithotripsy (FURL) for the treatment of renal calculus ≤2 cm .Methods Totally 148 patients with kidney stone ≤2 cm whom have taken operation treatment in our hospital were chosen from January 2014 to December 2014 .Among them ,81 patients were taken PCNL treatment (PCNL group) and 67 patients were taken FURL treatment (FURL group) .Clinical curative effect were compared .Results There was no statistically significant difference in the comparison of stone clearance rate ,fever rate and postoperative WBC increase (P>0 .05);the operation time of PCNL group (64 .21 ± 11 .71)min was shorten than the FURL group (107 .32 ± 16 .35)min ,the postoperative hospital stay of PCNL group (6 .51 ± 1 .92)d was longer than the FURL group (3 .28 ± 1 .24)d ,the Hb decrease after operation of PCNL group (13 .31 ± 2 .71)g/L was higher than the FURL group (3 .88 ± 2 .10)g/L , the postoperative hs CRP increase of PCNL group (14 .21 ± 1 .62)mg/L was higher than the FURL group (5 .23 ± 1 .14)mg/L ,the differences were statistically significant (P<0 .05) .Conclusion For the treatment of renal calculus ≤2 cm ,the FURL has a great advantage on reducing postoperative complications ,decreasing the trauma of operation and shorten postoperative hospital stay .

Compared the clinical effect with X-ray or B ultrasound guided puncture target calyces of treatment upper urinary calculi in MPCNL / 国际外科学杂志

Objective To compare with the efficiency between X-ray or B ultrasound guided puncture target calyces of treatment of upper urinary calculi in MPCNL.Methods From October 2010 to October 2012,we have a retrospective analysis of the 116 cases in urological department in the second affiliated hospital of Kunming Medical University,it had the sugery that was MPCNL.Selected 116 cases as the research object,(8 patients were lost to follow-up).With X-ray locating (48 cases),B ultrasound locating (53 cases),and compared with preoperative,intraoperative and postoperative clinical objective indicators of two different methods.Results X-ray locating (48 cases),the mean age was (44.86 ± 12.84) years; the mean Stone diameter(1.43 ±0.70) cm; Stone is located in the upper calyx in 1 case,the middle of calyx in 23 cases,under the calyx in 8 cases,the upper ureter in 16 cases.B ultrasonic locating (53 cases),the mean age was(46.36 ± 14.29) years; the mean Stone diameter (1.34 ±0.62) cm; Stone is located in the upper calyx in 2 cases,the middle of calyx in 24 cases,under the calyx in 8 cases,the upper ureter in 16 cases.Compared with preoperative general data of two groups,there was no statistically significant difference (P ＞ 0.05).X-ray group,the mean operation time (130.43 ± 31.63) min ; Intraoperative blood loss(80.42 ± 43.75) mL; Postoperative hospital stay (6.20 ± 2.08) d; Infected with 8 cases (17％) of postoperative,hemorrhage in 2 cases (4％) ; and calculi exhausted rate was 90％ (43/47).B Ultrasound group,the mean operation time(102.45 ± 36.32) min.Intraoperative blood loss(160.07 ± 52.33) mL;Postoperative hospital stay(5.62 ±2.37) d; Infected with 16 cases (30％) of postoperative,bleeding in 9 cases (17％) ; and calculi exhausted rate was 83％ (46/53).By comparison,X-ray and B ultrasound group in operation time,intraoperative blood loss,postoperative infection,a stone exhausted rate was statistically significant (P ＜0.05),and postoperative hospital stay,no statistical significance (P ＞ 0.05).Conclusion X-ray positioning compared with B ultrasound,X-ray is longer than B ultrasonic of operation time,but,blood much less,calculi exhausted rate is higher,and infected rate is lower.

Effect of minimally invasive percutaneous nephrolithotomy in treatment of recurrence of kidney stones after open operation / 中国基层医药

Objective To explore the curative effect of minimally invasive percutaneous nephrolithotomy in treatment of recurrence of kidney stones after open operation.Methods 56 patients with postoperative recurrence of renalcalculi were retrospectively reviewed.They were randomly divided into the control group and the observation group.The observation group was treated by minimally invasive percutaneous nephrolithotomy,while the control group received the open operation.The stone clearance rate,operation time and hospitalization time of the two groups were compared.Results The stone clearance rate in the observation group was 92.86％,which was significantly higher than 64.29％ of the control group (x2 =11.37,P ＜ 0.05) ; The average operation time in the control group was (131.8 ± 8.9)min,which was more than (92.5 ± 5.4)min of the observation group ;The average hospital stay in the control group was (19.7 ± 3.2) days,which was more than (10.4 ± 2.6)days of the observation group,the differences were statistically significant (t =16.38,17.25,all P ＜0.05).Conclusion Minimally invasive percutaneous nephrolithotomy can improve the stone clearance rate in treatment of recurrent renal calculi after open operation,which can shorten the operation time and hospital stay,it is worth the clinical promotion.

The risk factors of residual stones after single channel percutaneous nephrolithotomy / 重庆医学

Objective To investigate the risk factors and countermeasure of residual stones after single‐channel percutaneous nephrolithotomy for higher stone‐free rate and better operation result .Methods All patients who underwent single‐channel percu‐taneous nephrolithotomy in our hospital from June 2011 to December 2013 were retrospected and the cause of residual stones were analyzed .Results There were 42 patients who had residual stones after operation among total 262 patients undergone single‐chan‐nel PCNL .21 patients had residual stones because the stones they burdened were too complex .7 patients were concerned with com‐plications such as intraoperative hemorrhage .The stone fragments scattered into the calices in 7 patients with overlarge stone during fragmentation .The other causes concerned with stone residue included anatomic structural abnormalities of the kidneys(3 patients) , operation itself inherent limitations(3 patients) ,insufficient practice and experience in operation(1 patients) .Conclusion The main causes concerned with residual stones of single‐channel PCNL are complexity of urinary calculi ,bleeding ,scattering of stone frag‐ments and anatomic structural abnormalities of the kidney .